From the very earliest stages of language learning, children gesture as they talk. In adults, gesture is integrated with the speech it accompanies, often conveying information that is related, but not identical, to the information conveyed in that speech. Gesture can thus expand a speaker's communicative range. Project II builds on previously collected longitudinal obervations of 60 children, ages 14 months to school entry, whose families were chosen to represent the demographic range of Chicago. The project observes gesture in these children who will be followed as they enter school until age 10. In addition to providing normative gesture data for the brain injured children in Project III, Project II has three specific aims. (1) Given that gesture can serve as a window that is distinct from speech into the child's communicative abilities during the early stages of language-learning, the first aim is to characterize the way gesture is used in later stages of language-learning as children begin school. Study 1 asks whether gesture continues to expand the children's communicative repertoires in the later years, providing the first sign of more complex syntactic constructions and new discourse devices. (2) Given individual differences in how children use gesture during the early stages of language-learning, the second aim is to explore whether those differences predict later language use. Study 2 asks whether gesture not only opens the door for languagelearning but also sets the learning trajectory. (3) The third aim is to explore whether gesture plays a causal role in language-learning. Study 3 experimentally manipulates gesture in 144 additional 1-word speakers and observes the effect of this manipulation on their vocabulary and their transition to 2-word speech. While most children successfully acquire the language to which they are exposed, some achieve mastery later than others. The timing of each milestone may be important for its effect on the eventual outcome of language acquisition, as well as for its impact on other cognitive skills. Project II explores whether gesturing also varies, and, if so, how that variability is related to variability in later languagelearning. Given that there are individual differences in how often families use gesture, it becomes important to determine whether gesture plays a role in language-learning. If so, educators need to become aware of the skills children display in the nonverbal realm, and learn to use them to improve verbal skills.